Immunoprecipitation of JPH2 and RYR2 from hearts of FL, MCK-FKD, MHC-Cre⁺ and MHC-FKD. JPH2 and RYR2 were immunoprecipitated from hearts of FL, MCK-FKD and MHC-FKD mice using procedures we have previously described (Lee et al., 2023). Proteins in the IP were identified by mass spectrometry. (A) Volcano plot of the JPH2 binding proteins from the hearts of FL mice. (B) A volcano plot of the JPH2 binding proteins from the hearts of MCK-FKD mice. (C) A volcano plot of the JPH2 binding proteins from the hearts of MHC-FKD mice. (D) Volcano plot of the RYR2 binding proteins from the hearts of FL mice. (E) Volcano plot of the RYR2 binding proteins from the hearts of MCK-FKD mice. (F) Volcano plot of the RYR2 binding proteins from the hearts of MHC-FKD mice. (G) Normalized FKBP12.6 in RYR2 IPs. (H) Phosphorylation of RYR2 from PRM at the SPEG phosphorylation site. In these studies, we could not distinguish between phosphorylation at S2367 and S2368. (I) Phosphorylation of RYR2 by PRM at the PKA phosphorylation site (S2807). No differences were detected among FL, MCK-FKD, and MHC-FKD in either the JPH2 or RYR2 IPs. JPH2 IPs: n = 11 for each genotype. RYR2 IPs, FL, n = 7, MCK-FKD, n = 10, MHC-FKD, n = 10. Data in G–I are shown as mean ± SD.